RE: qshell, ls, sort by size

On Wed, 27 May 2009, Evan Harris wrote:

Clunky old OS/400 with its pathetic verbose text interface would force you to type something obvious like ORDERBY(*SIZE) as the parameter determining sort key. Anyone can see the OS/400 approach is clearly inferior - we all prefer cryptic terse statements to longer self-documenting statements...

I think that the strength of the command prompting and verbosity in OS/400 is also its Achilles heel. Clearly in some situations having all that verbosity is useful and very welcome. But equally in others I feel it is a pain in the neck. I believe that in general commands on both systems are used by rather experienced users. I've been using both for around 15 years. I have discovered that even after all this time there are very few OS/400 commands that I can use without prompting and all of them take an awful lot of typing. On the other hand, the terse unix shell commands have all managed to stick in my memory and I quickly navigate and work on the system without slowdowns. For me, the unix shell commands are far easier to use because they are more efficient to type in! Some examples of things I routinely do:

list all files/objects in my home directory/library:

shell: ls
OS/400: WRKOBJ OBJ(JAMES/*ALL)

Show running jobs/processes:

shell: ps ax
OS/400: WRKACTJOB

Delete files/programs/objects/etc. in my home directory/library:
shell: rm *~ *.o tmpfile?? (many ways to select files)
OS/400: DLTMOD MODULE(JAMES/MOD*), then DLTPGM PGM(JAMES/PGM*) (doesn't have as useful regex for selecting what to delete and also requires a different command for each object type)

So in these cases for me the verbosity is a detriment. Even these examples I had to use prompting to determine what parameter DLTMOD takes: MODULE or MOD. I think this is what many unix designers realized - that the efficiency of a relatively terse command tends to outweigh the obviousness of a verbose command when both are used by an experienced user.

This is in contrast to a programming language. Because a program is a static work (i.e. the code is useful for more than one execution), it is more important to be descriptive than it is to be quick to type in. But while you can make scripts from commands, the most common usage of a command is to do something now and do it once (i.e. show me what files are in my directory). I'm not saving the commands I type in for someone else to run and understand, I'm just trying to clear out temporary files and efficiency of entry trumps verbosity in this case. For this reason, let your programming be verbose but let your commands be succinct!

James Rich

if you want to understand why that is, there are many good books on
the design of operating systems. please pass them along to redmond
when you're done reading them :)
- Paul Davis on ardour-dev